Process of making pipe and in a special form of pipe



Dec. 11 1923.

F. T. SNYDER PRoEss cF MAKING PIPE AND 1N A SPECIAL Poma 0F PIPE Filed May 2'?. 1920 2 sheets-Sheet 1 INVENTOR Dec. l1, 1923. 1,476,734

F. T. SNYDER PROCESS OF MAKING PIPE AND IN A SPECIAL FORM OF PIPE Filed May 27. 1920 2 Sheets-Sheet 2 INVENTOR Patented Der.. li, 1923.

FREDERICK T. SNYDER, OF NEW YORK, N. Y.

PROCESS OF MKING PPE AND N .A SPECIAL FORM OIE EIPE;

Application led May 27,

@ZZ whom it may concern:

Be it known that l, FREDERICK T. SNYDnn, residing at New York, in the county and State of New York, have invented new and useful Improvements in the Process of Making Pipe and in a Special Form of Pipe, of which the following is a specification.

My invention relates to a method and apparatus forl making cast steel pipe in a particular form. Heretofore iron pipe has been made in two forms. One form was made from cast iron by pouring molten cast iron into sand molds. The other form was made from wrought iron by rolling iron strips up edgeways and welding the seam. (last iron pipe is che-ap to make, but brittle and heavy to use. l/Vrought iron pipe is light and strong, but high in cost to make. in later years pipe has also been made from rolled strips of malleable steel, forming lap welded steel pipe. This, is light and stronger than rolled iron pipe, but is also high in cost.

My invention consists in a form of pipe and a method and apparatus for making it, by which I am able to east steel pipe, which is as light and strong as rolled steel pipe, and also has the low cost of production of cast iron pipe. Like cast iron pipe it also has the advantage of having no longitudinal seam. Such seams tend to open when the pipe is bent and leak oil and gas. Steel does not flow as readily as cast iron. In the thicknesses used for standard pipe liquid cast steel will not flow much further than half the circumference of the pipe, before the leading edge of the steel stream chills and solidifies. In casting iron pipe in a horizontal mold, the metal is fed in through a number of gates, distributed along the length of the pipe. This is not practical in casting steel pipe, due to the much greater shrinkage of steel in cooling. A ten foot length of cast steel pipe shrinks two and one half inches in cooling. Tf side pouring gates were used with steel as with cast iron pipe, the gates would be held by the sand and cause the steel pipe to tear in contracting.V The form of pipe and casting methodrof my invention avoids this combined difiiculty by making the casting gate integral with the pipe and extending lengthways of the pipe. There is, therefore, no change in sectional size to catch on the sand and the steel is free to contract in cooling. At the same time no part of the flowing steel has to flow through 1920. serial No. 384,766.

the thin pipe sectionl for va distance greater than the circumference of the pipe.

There are additional features of my invention which I will describe more fully hereafter. The accompanying two sheets of drawings diagrammatically illustrate my preferred form of pipe and apparatus for producing it.

ln the drawings Fig. 1 is a view in elevation of the pipe looking from the points ofthe arrows e-16 in Fig. 3;

Fig. 2 is a fragmentary cross sectional view through the pipe; Y

Fig. 3 is a transverse sectional view through such pipe;

Fig. 4l is a horizontal sectional view taken on the line 23-24 of Fig. 5; and

Fig.y 5 is a vertical sectional view taken on the line 21-22 of Fig. 4f

Fig. 3 is a cross section through the pipe of my invention. At 11 is shown the cast steel. VCoating this, both inside and-outside of the pipe is a layer of sand 12 which is burned onto the steel. At 13 is shown the gate through which the steel is poured in casting the pipe. Directly opposite is shown a second gate 14 which serves as an escape for the gas and air from the mold while the steel is running into the irst gate 13. This second gate by changing the section also acts to `break up the metal stream as it runs around the pipe andk so opens up fresh molten surfaces for the two streams coming inv opposite directions around the pipe, to join. It will be noted that'the surfaces of these gates 13 and 14C are tangent to the surface of the pipe. It has beenrfound that longitudinal grooves or corners when the gates join the pipe lead to cracksin the cooled casting. The thickness at the gates is about` twice the thickness of the pipe between the gates.

Fig. 1 is an elevational view of the pipe taken from the direction of the arrows 15 and 16 of Fig. 3, the left hand of the center line showing the pouring gate and the right hand showing the pipe between lthe gates.A At 17 is shown the are weld by which the lengths of pipe as cast are joined together. To prepare for this joint the extra thickness of the gates is cut back as shown at 18. Fig. 2 is a longitudinal section through the welded joint at a point away from the gates. The ends of the cast steel pipe are first ground square with the axis of the pipe as shown at 19., The outside of the joint is then beveled as shown at 20, the bevel not extending entirely through to the inside. The flat close joint left prevents the welding metal from running through and forming beads on the inside of the pipe. fhe joint is then filled with the weld l? which forms an integral partwith both sections of the pipe. es this cast steel pipe'has no longitudinal sea-m, welding the circun'iferential joints makes a completely tight con# duit,` free from leaks of gas or oil. lf desired, the lengths of the cast steel pipe may Abe threaded and the ends joined by couplings the line 23--24 of the vertical cross-section.

At 25 is shown the space into which the pipeis to be poured. At 26 is the enlarged space that forms the pouring gate, integral with the pipe. At 27 is the duplicate enlarged space through which the steam and gases esca-pe from the mold while the metal is flowing' down the space 26. At 28 is shown the pouring basin7 into which the molten metal is poured from a ladle. When theppouring is complete, this basin is filled with metal and serves as. a feeding head to supply metal to the enlargements 26 and 27 as the casting cools, and so prevent shrinkage holes.

The mold in which the pipe is cast is lined with molding sand 29-30 both o-n the inside and outside of the pipe. This sand 29 is supported on the outside by a cast iron flask Bl which is made in halves, hinged together on one side by hinges 32 and held together on the other side by wedged clamps 33. n the inside yof the pipe the sand is supported by a mandrel 34, made of a piece of pipe. Both `the flask and the mandrel are perforated to allow the escape of steam and gas from the sand. Y

in making a mold, the flask 31 is closed and clamped together and stood vertically on'its feet 35 on a jolt ramming machine. A brass pattern of they pipe is lowered into the fiask'until it reaches the conical bottom 35 of the flask 3l. which serves to center the pipe pattern in the flask. The mandrel 34 is then Vlowered into the pipe pattern, until :he mandrel also rests in and is centered by the conical bottom 35 of the ask 3l. Sand is then introduced between the pattern and the flask and between the pattern and the mandreland rammed by jolting the flask on the Jolting machine. This jolted sand is leveled ofi" even with the top of the flask at 36, both inside and outside the pattern. A smooth. iron 3'? is placed on top of the nevera-i sand inside the pipe and a pouring head 38 of dry baked sand is placed on top the sand outside the pattern. rlhis ring 37 and head 38 serve to ho-ld down the sand when the pattern is drawn out of the mold. The pouring head is of sand baked in an iron frame 39. After the pattern is out thev iron ring 37 is removed and replaced by a dry sand ring the saine size and shape.

rilhe nietalis poured in the basin 28 in the i pouring head 38 and flows down into the spaces -26 and forms the pipe. As soon as the pipe is poured, the mandrel 34 is removed by a hook placed in the hole 4:1. rl`his leaves the sand inside the pipe unsupported and therefore able to crumble and move in as the cast pipe shrinks in diameter in coo-ling. As pieces of this inner sand drj,T out and drop off', they fall out of the hole 4t2 in the `center of the conical bottom 35 of the flask 81. This prevents the sand from packing in the bottom of the cast pipe and so keeping it from contracting as it cools and so avoids cracks. `When the pipe is solid, but yet red hot, the clamps 83 are released and the flask opened on the hinges 32 and the cast pipe released.

ll'ihen the sand is mixed for making the mold, the mixture is so compounded that the f sand will be somewhat .fusibile at the temperature at which the metal runs into the iold. It results from this that a layer of sand 12-l2 fuses onto the cast pipe. This sand layer is substantially impervious to water and air and serves to keep the finished pipe from rusting.

While I have herein shown and particularly described the preferred embodiment of my invention which is well adapted'to the practice of my method, l do not wish to be limited thereto.

Having thus described my invention, I claim as new and desire to secure by Letters Patent the following l. The method of casting pipe which consists in formino the mold for such pipe with a thickened portion, the surfaces of suc-h portion being tangential to the circumference of said pipe and pouring the metal to form such pipe through such thickened portion.

2. The method of casting pipe which consist-s in forming two enlarged nchannels in the mold at the circumference of said pipe, pouring metal into one of said channels and permitting the gases to escape from the mold `through the other said channels.

The method of'casting pipe which con sists in pouring themetal through two thin sections into a thicker section, whereby the cooled edges of the streams of metal are disturbed and fresh surfaces exposed for the joining' ofthe two streams of metal.

saisonnier: T. sNYn'n-a. 

